In general, a switching power supply is used to supply power to a load in an electronic device or the like. For example, a direct-current-to-direct-current (DC-DC) converter that converts a DC voltage into another DC voltage is used. A power supply integrated circuit (IC) that includes a plurality of DC-DC converters and may supply different output voltages from channels is known. When switching timings of channels adjacent to each other become close in the power supply IC including the plurality of DC-DC converters, input current may momentarily increase. The momentary increase of the input current may produce switching noise. For example, WO 2006/046372 A1 discusses a configuration in which ON periods of switching signals of adjacent channels are shifted so as not to overlap.
When a plurality of DC-DC converters to which an input voltage is applied in common include a DC-DC converter in which a switching timing depends on a factor other than a clock signal, and when switching timings of the DC-DC converters become close, switching noise may occur.